Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area

Transcription

1 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area Prepared for Niagara Peninsula Source Protection Authority 250 Thorold Road West, rd Floor Welland, ON LC W2 Prepared by November 0, 2009 (numerical amendments made in June, 2011)

2 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area Table of Contents 1. INTRODUCTION BACKGROUND HYDROGEOLOGICAL CONCEPTUALIZATION TECHNICAL RULES METHODOLOGY REVIEW AND ASSESS AVAILABLE DATA AND INTERPRETATIONS ASSESS VULNERABILITY Intrinsic Susceptibility Index (GwISI) Aquifer Vulnerability Index (AVI) Combined Groundwater Vulnerability VULNERABILITY INCREASE FOR TRANSPORT PATHWAYS Wells, existing Wells, abandoned Oil and Gas Wells Aggregate Operations Construction Activities along the Welland Canal Transport Pathways Summary VULNERABILITY HIGHLY VULNERABLE AQUIFERS (HVAS) SIGNIFICANT GROUNDWATER RECHARGE AREAS (SGRAS) UNCERTAINTY NEXT STEPS POTENTIAL SOURCE PROTECTION PLAN CONCEPTS PROVINCIAL POLICY STATEMENT Contaminant Management Emerging Challenges FUTURE UPDATES DATA GAPS REFERENCES NPCA 1

3 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area List of Tables Table 2.1 Table 2.2 Table 2. Table.1 Table.2 Table. GwISI/AVI Vulnerability Results Aggregate Resources and Construction GwISI/AVI/Transport Pathway Vulnerability Results SGRA Groundwater Vulnerability Distribution SGRAs Vulnerability Score Qualification of Uncertainty List of Figures Figure 1.1 Study Area Figure 1.2 NPSP Area Prominent Surficial Overburden Aquifers Figure 1. NPSP Area Contact-Zone and Prominent Bedrock Aquifers Figure 2.1 Rule 7(1)/8(1) Groundwater Vulnerability Intrinsic Susceptibility Index Figure 2.2 Overburden Thickness Figure 2. Rule 7(2)/8(1) Groundwater Vulnerability Aquifer Vulnerability Index Figure 2.4 Groundwater Vulnerability Rules 7(1)/7(2)/8(1) Figure 2.5 Transport Pathways Figure 2.6 Groundwater Vulnerability Rules 7,8,9 and 40 Figure.1 Highly Vulnerable Aquifers Figure.2 Significant Groundwater Recharge Area Vulnerability Appendices Appendix A: Regional Conceptual Cross-sections Appendix B: Existing Vulnerability Mapping Review was revised Appendix C: Peer Review Record NPCA 2

4 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area 1. INTRODUCTION The Assessment Report Technical Rules (Ministry of the Environment, 2009) require vulnerability mapping to be prepared of highly vulnerable aquifers (HVAs) and significant groundwater recharge areas (SGRAs). These vulnerability maps are to account for transport pathways which can increase the vulnerability of an aquifer. For future evaluation of drinking water threats, vulnerability scores are assigned to the delineated HVAs and SGRAs. This Groundwater Vulnerability Assessment was completed to address these requirements for the Niagara Peninsula Source Protection (NPSP) Area (Figure 1.1) as described in Part IV, Part V.I, Part VII.1 and Part VII.2 of the Assessment Report Technical Rules: Part IV describes methods for assigning groundwater vulnerability including the identification of areas where the vulnerability may be increased due to the presence of transport pathways; Part V.I describes the delineation of HVAs; and Part VII.1 and Part VII.2 describe the assignment of vulnerability scores to HVAs and SGRAs, respectively. 1.1 Background The Niagara Peninsula Conservation Authority Groundwater Study (Waterloo Hydrogeologic Inc., 2005) completed aquifer vulnerability mapping as part of its groundwater study. The study used two vulnerability assessment methods that are listed under the Assessment Report Technical Rules Part IV.1 Rule 7: (i) intrinsic susceptibility index (GwISI) (Figure B.5) and (ii) aquifer vulnerability index (AVI) (Figure B.9). This mapping has been presented in the NPSP Area Watershed Characterization report (Niagara Peninsula Conservation Authority, 2009) (Figure B.10). SGRAs were mapped according to the Assessment Report Technical Rules Part V.2, as part of the Tier 1 Water Budget and Water Quantity Stress Assessment (Niagara Peninsula Conservation Authority and AquaResource Inc., 2009). 1.2 Hydrogeological Conceptualization The regional hydrogeological setting has been summarized from other Source Water Protection studies completed for the NPSP Area. NPSP Area aquifers can considered as four (4) main types: (i) Surficial overburden; i.e. the Fonthill Kame-Delta Complex, the Dunnville Sand Plain and the Iroquois Sand Plain (Figure 1.2). These are unconfined aquifers consisting of coarse-grained deposits. (ii) The Guelph/Lockport Formations (Figure 1.), these bedrock aquifers range from (a) unconfined where they are exposed along the Niagara Escarpment, to (b) semi-confined beneath fractured/weathered overburden to (c) confined where overlain by greater than 5 m of overburden. These consist of mostly dolostone NPCA

5 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area (iii) (iv) with some limestone limestone portions. Fracturing is expected to be greater where exposed at surface. Onondaga/Bois Blanc Formations; (Figure 1.), these bedrock aquifers also range from (a) unconfined where they are exposed along the Onondaga Escarpment, to (b) semi-confined beneath fractured/weathered overburden to (c) confined where overlain by greater than 5 m of overburden. These consist of dolostone and limestone. Fracturing is expected to be greater where exposed at surface. Contact zone or the basal granular and top of bedrock aquifer (Figure 1.), is a regional aquifer generally considered confined. It consists of granular overburden and fractured bedrock overlain by clay. These units are also shown in regional cross-sections in Appendix A. Although there are no current municipal groundwater systems in the NPSP Area, private water supplies serve over 77,000 people in the NPSP Area. The number serviced by aquifer units may be less, as only 6,600 private drinking water wells are on file in the NPSP Area Ministry of the Environment (MOE) water well information system (WWIS). However, many dug wells are not in this provincial database and cisterns are used very widely in the NPSP Area. 1. Technical Rules The Assessment Report Technical Rules (MOE, 2009) provide the following instructions for the delineation of groundwater vulnerability. Rules concerning municipal wellhead protection areas were not included, e.g. rule 8.1, as there are no municipal wellhead protection areas in the NPSP Area. Assessment Report Technical Rules 1, 14 and 15 are presented separately under the Uncertainty Analysis Section.. Part IV.1 Vulnerability Assessment and Delineation, Groundwater 7. The vulnerability of groundwater within a source protection area shall be assessed using one or more of the following groundwater vulnerability assessment methods, (1) Intrinsic susceptibility index; (2) Aquifer vulnerability index; () Surface to aquifer advection time; (4) Surface to well advection time, or 8. A source protection area shall be divided into areas of high, medium or low groundwater vulnerability, high corresponding to greater vulnerability as follows; (1) Where a method described in subrule 7(1) or (2) was used to assess vulnerability; (a) Areas of high vulnerability are those areas with scores that are less than 0, (b) Areas of medium vulnerability are those areas with scores that are greater than or equal to 0 but less than or equal to 80, and NPCA 4

6 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area (c) Areas of low vulnerability are those areas with scores that are greater than 80; (2) Where a method described in subrule 7() or (4) was used to assess vulnerability; (a) Areas of high vulnerability are those areas with results that are less than 5 years; (b) Areas of medium vulnerability are those areas with results that are greater than or equal to 5 years but less than or equal to 25 years, and (c) Areas of low vulnerability are those areas with results that are greater than 25 years, or () Where, in accordance with rule 15.1, a method that departs from the methods specified in rule 7 has been used, to assess vulnerability, an approach shall be used that, in the Director s opinion, is comparable to the approach specified in subrules (1) and (2). 8.2 If more than one method is used to assess groundwater vulnerability, the results of both methods should be mapped separately. Vulnerability increase, transport pathways 9. Where the vulnerability of an area identified as low in accordance with rule 8 is increased because of the presence of a transport pathway that is anthropogenic in origin, the area shall be identified as an area of medium or high vulnerability, high corresponding to greater vulnerability. 40. Where the vulnerability of an area identified as medium in accordance with rule 8 is increased because of the presence of a transport pathway that is anthropogenic in origin, the area shall be identified as an area of high vulnerability. 41. When determining whether the vulnerability of an area is increased for the purpose of rules 9 and 40 and the degree of the increase, the following factors shall be considered: (1) hydrogeological conditions; (2) the type and design of any transport pathways; () the cumulative impact of any transport pathways; and (4) the extent of any assumptions used in the assessment of the vulnerability of the groundwater. Part VII.1 Highly vulnerable aquifers 79. A highly vulnerable aquifer shall be assigned a vulnerability score of 6. NPCA 5

7 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area Part VII.2 Significant groundwater recharge areas 80. A significant groundwater recharge area shall be subdivided by the areas of groundwater vulnerability identified in accordance with Part IV rule The areas identified in accordance with rule 80 shall be assigned a vulnerability score of; (1) 6, where the groundwater vulnerability for the area is high; (2) 4, where the groundwater vulnerability for the area is medium; or () 2, where the groundwater vulnerability for the area is low. NPCA 6

8 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area 2. Methodology The five (5) steps of the Groundwater Vulnerability Assessment included: Step 1: Review and assess available data and interpretations Section 2.1 Step 2: Assess Vulnerability Section 2.2 Step : Consider Vulnerability Increase for Transport Pathways Section 2. Step 4: Assign Vulnerability Score Section.1 and.2 Step 5: Evaluate Uncertainty Section. Information from these steps was evaluated semi-quantitatively using a methodology adapted from Jagger Hims Limited (2009). The scoring system was assigned to estimate the confidence in the available data and in each of the assessment phases. Data sources: Site Selection and Assessment Reports prepared by Gartner Lee Limited in 1985 and 1987 on behalf of Waste Management Corporation Water Resources of the Niagara Frontier and the Welland River Drainage Basin Report prepared by Gartner Lee Limited in 1987 on behalf of the Ministry of the Environment Niagara Water Quality Protection Strategy prepared by CH2MHill, MacViro and Philips Engineering in 200 on behalf of the Regional Municipality of Niagara and the Niagara Peninsula Conservation Authority Surficial geology and permeability mapping prepared by the Geological Survey in 1997 and 200 for the Ministry of Northern Development and Mines Niagara Peninsula Conservation Authority Groundwater Study prepared by Waterloo Hydrogeologic Inc. in 2005 for the Niagara Peninsula Conservation Authority Hamilton Groundwater Resources Characterization and Wellhead Protection Partnership Study prepared by Charlesworth and Associates and SNC-Lavalin Engineerings and Constructors in 2006 for the City of Hamilton Draft Groundwater Resources Study prepared by the Hamilton Conservation Authority for the Geological Survey Aquifer Vulnerability Mapping prepared by EarthFx in 2008 for the Source Protection Region Significant Groundwater Recharge Areas Report prepared by the Niagara Peninsula Conservation Authority and AquaResource Inc. in 2009 for the NPSP Authority Ministry of the Environment Water Well Information System (2006) Oil, Gas and Salt Resources Library (2009) Ministry of Natural Resources historical pits and quarries and authorized aggregate sites NPCA 7

9 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area 2.1 Review and assess available data and interpretations Regional-scale NPSP Area groundwater vulnerability maps were reviewed for their suitability in the vulnerability assessment (Appendix B). From this review it was determined that the Niagara Peninsula Conservation Authority (NPCA) Groundwater Study (Waterloo Hydrogeologic Inc., 2005) mapping was most suitable basis for the groundwater vulnerability analysis. This was because: 1) It was produced using groundwater vulnerability assessment methods that are approved in the Assessment Report Technical Rules; and 2) It was the only map product which was seamless across the NPSP Area. Waterloo Hydrogeologic Inc. assessed this groundwater vulnerability using GwISI and AVI methods, Assessment Report Technical Rules 7 (1) and 7 (2), respectively. The GwISI analysis was completed of the entire study area using MOE WWIS. The AVI analysis was only completed with respect to (i) surficial overburden and (ii) bedrock at surface aquifers, e.g. the Fonthill Kame-Delta Complex and Niagara and Onondaga Escarpments, respectively. The final NPCA Groundwater Study groundwater vulnerability map was a conservative combination of the two methods. The GwISI results were similar to other consultants adjacent maps in the City of Hamilton and Haldimand County where the MOE WWIS was the principal dataset (Appendix B). 2.2 Assess Vulnerability The Groundwater Vulnerability was assessed by considering the suitability of the vulnerability as assessed by the following methods: Intrinsic Susceptibility Index (GwISI); and Aquifer Vulnerability Index (AVI) (based on regional hydrostratigraphic interpretations) Intrinsic Susceptibility Index (GwISI) As mentioned above, the GwISI map (Figure 2.1) was obtained from the NPCA Groundwater Study (Waterloo Hydrogeologic Inc., 2005). Details of the GwISI methodology are provided in Appendix B. The GwISI map is considered to reflect the vulnerability either to the water table aquifer or to the first confined aquifer layer. The vulnerability is based upon the following matrix: GwISI/AVI Score <0 High 0-80 Medium >80 Low Vulnerability Review of the GwISI against available regional hydrostratigraphic interpretations suggests that the distribution of high vulnerability is under-estimated in some areas. This is a limitation of digital contouring to map linear features, e.g. the Niagara Escarpment. NPCA 8

10 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area It is also a limitation of the distribution of the MOE WWIS dataset, both vertically, where there are multiple aquifers, and horizontally, between available well records. Despite these limitations the GwISI was considered a good basis for the vulnerability assessment but needing the improvement of some additional AVI mapping Aquifer Vulnerability Index (AVI) AVI groundwater vulnerability assessments were also completed to improve the delineation of highly vulnerable aquifers. The specific aquifers considered were: I. surficial water table aquifers (both overburden and bedrock); and II. unconfined/semi-confined bedrock aquifers (i.e. having less than 5 metres of overburden). The AVI groundwater vulnerability assessments were based on regional hydrostratigraphic interpretations (Section 1.2) and K-Factor assignments based on the aquifer/aquitard designation and the overburden thickness (Figure 2.2). The AVI for the surficial water table aquifers correspond with High. The AVI for the semi-confined bedrock aquifers also correspond with High. The extent of the AVI vulnerability assessments for highly vulnerable aquifers are shown on Figure Combined Groundwater Vulnerability The combined GwISI and AVI vulnerability assessments are presented on Figure 2.4 and tabulated in Table 2.1. Table 2.1 GwISI/AVI Vulnerability Results High Medium Low Boundary (size km 2 ) km 2 % km 2 % km 2 % NPCA (2,409) % 740 1% 1,05 44% Niagara Region (1,871) % % % City of Hamilton (27) 29 12% % % Haldimand County (02) 47 16% 79 26% % Note: some disagreement between sum areas and individual values is caused by rounding of significant digits The results of the mapping indicate the following as modified from the NPCA Groundwater Study (Section., Waterloo Hydrogeologic Inc., 2005): Areas of low susceptibility occur mainly in the central portions of the NPSP Area, and correspond to thick deposits of clay and silt of the Haldimand Clay Plain. This material, below 5 m BGS, restricts the downward movement of infiltrating surface water, making the underlying groundwater much less susceptible to associated contamination. NPCA 9

11 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area Areas of high susceptibility: 1. Occur mainly in the presence of high permeability overburden units with little, or no, low conductivity layers overlying the aquifer. These include the Fonthill Kame-Delta Complex, the Iroqouis Sand Plain, and the Dunnville Sand Plain. 2. Occur where the bedrock outcrops or is overlain by thin (i.e. <5 m) deposits. 2. Vulnerability Increase for Transport Pathways The transport pathways that were considered to have potential to increase groundwater vulnerability are (Figures 2.5a, b, c and d): Private water wells (including abandoned wells needing decommissioning) Unknown status oil and gas wells Aggregate operations; and Construction activities along the Welland Canal. Other transport pathways, such as septic systems, storm water facilities and sanitary sewers, were not included as they are not likely to increase this regional groundwater vulnerability mapping. Explained further: Installation of in-ground septic systems only marginally increases groundwater vulnerability through removal of an upper soil layer, however they are still sources of contaminants, i.e. for potential consideration under threats and issues evaluations. Stormwater facilities are largely not infiltration basins in NPCA. Areas where infiltration facilities have been constructed are already classified as highly vulnerable, e.g. Fonthil Kame-Delta Complex. Sanitary sewers can laterally transmit contaminants however they are generally overlain by impervious surfaces. This study is primarily concerned with vertical vulnerability but they are still sources of contaminants i.e. for potential consideration under threats and issues evaluations Wells, existing Private wells are considered to have the potential to increase groundwater vulnerability as transport pathways. Well clusters are identified as priority risks because of the high-density of wells connected to the underlying aquifer. Well clusters were defined as being six wells located within 100 m radius of each other (Jagger Hims Limited, 2009). This analysis was completed using MOE WWIS and Ministry of Natural Resources (MNR) oil and gas well records, but not including officially abandoned records. The groundwater vulnerability has been raised to high for a 0 m radius around each individual well (Figures 2.5a, b, c and d). A 0 m radius was chosen based on the recommended setback distance from contamination sources in Regulation 90 (Wells Regulation) as amended (this distance has also been incorporated in the Building Code). There were 750 wells identified in this analysis, only one was from the MNR dataset. Wells older than 10 years old (pre-2000) were also considered transport pathways to potentially increase groundwater vulnerability. This is because newer wells are likely to NPCA 10

12 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area be constructed to a higher standard and therefore a lower risk. The groundwater vulnerability has been raised to high for a 0 m radius around each of these 8,548 wells (Figures 2.5a, b, c and d). In each of these cases the vulnerability was increased to high from either medium or low. This is because by its very nature a well is constructed as a pathway from the surface to the aquifer through the naturally protective layers, if present Wells, abandoned There are 1,479 MOE WWIS records of former water supply wells in areas now serviced by municipal water. These transport pathways also present a high risk to the underlying aquifers. The groundwater vulnerability has been raised to high for parcels containing a well (Figures 2.5a, b, c and d). The groundwater vulnerability has been raised to high for a 0 m radius around each of the 2 well that were not located on parcels but roadways (Figures 2.5a, b, c and d). 2.. Oil and Gas Wells There are also oil and gas wells completed in the NPSP Area. Since the early 1990s, license requirements govern use and abandonment through the Ministry of Natural Resources. However the status of abandonment of some oil and gas wells prior to the 1990s is unknown. These earlier installations may not have been properly abandoned or plugged, i.e. they may not be sealed and if sealed, may not have been sealed in a method that will minimize the vulnerability of the shallow groundwater systems. Potentially un-plugged wells, status being unknown and generally pre-dating 1992, have been included as transport pathways. The groundwater vulnerability has been raised to high for parcels containing these wells as they pass through the water supply aquifers. There are 1,6 unknown status wells in NPSP Area land mass while there are additional wells offshore Aggregate Operations Aggregate operations, i.e. pits and quarries, are transport pathways reducing the amount of overlying material to filter and/or attenuate contaminants. In the NPSP Area there are 1 authorized aggregate sites, and 10 historic pit and quarry locations (Figures 2.5a, b, c and d). The vulnerability category for historic and licensed pits and quarries will be raised to high as there is no protection to the aquifer. These locations are already generally classed as highly vulnerable (Table 2.2) because they are sited where the resource is close to surface and correspond with overburden or bedrock aquifers. Table 2.2 Aggregate Resources and Construction GwISI/AVI Vulnerability Transport Pathway Vulnerability Area (km 2 ) Percent (%) High High Medium High Low High NPCA 11

13 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area 2..5 Construction Activities along the Welland Canal Construction activities can alter the natural environment through the removal of low permeability units. An example of this is the Welland Canal (Figures 2.5a, b, c and d). The canal s channel bed is directly on bedrock over two spans and acts as a source of recharge to the groundwater system (Frind, 1970), i.e. the contact zone aquifer. The St. Lawrence Seaway Management Corporation has confirmed that the two spans for which that the canal bottom is cut into bedrock are from (i) Glendale Avenue, St. Catharines to Hurricane Road, Thorold and from (ii) Ramey s Bend, south of Dain City southward to (Fraser Johnston, personal communication 2009). The susceptibility categories underlying these areas will be raised to high as there is no protection to the aquifer Transport Pathways Summary Following Assessment Report Technical Rules 9, 40 and 41, medium and low groundwater vulnerabilities were modified to high. This was based upon the presence of transport pathways that have the high potential to, or actually remove, natural groundwater protection to water supply aquifers (Figure 2.6). The overall increase in highly vulnerable aquifers from the consideration of transport pathways is 46 km 2 or about 2% of the NPSP Area (Table 2.). Most of this increase is mapped in Niagara Region and the City of Hamilton. Table 2. GwISI/AVI/Transport Pathway Vulnerability Results High Medium Low Boundary km 2 % km 2 % km 2 % (size km 2 ) NPCA (2,409) ,06 4 Niagara Region (1,871) City of Hamilton (27) Haldimand County (02) Note: some disagreement between sum areas and individual values is caused by rounding of significant digits NPCA 12

14 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area. Vulnerability.1 Highly Vulnerable Aquifers (HVAs) Highly vulnerable aquifers, i.e. areas of high groundwater vulnerability, were delineated for the NPSP Area based on the previously discussed analyses and are illustrated on Figure.1. The HVAs delineation reflects the increased vulnerability of the shallowest identified aquifers by transport pathways. As per Assessment Report Technical Rule 79, HVAs are assigned a vulnerability score of 6..2 Significant Groundwater Recharge Areas (SGRAs) Significant groundwater recharge areas (SGRAs) were previously mapped according to Assessment Report Technical Rules (Niagara Peninsula Conservation Authority and AquaResource Inc., 2009). The SGRAs cover 542 km 2 or about 22% of the NPSP Area based upon a criterion of 5 mm/year or greater (Figure.2). About half of the SGRAs are also mapped as highly vulnerable in the NPSP Area, as well as Niagara Region and Haldimand County (Table.1). Table.1 SGRA Groundwater Vulnerability Distribution Boundary (size km 2 ) SGRA size km 2 (% of Area) High km 2 (%) Medium km 2 (%) Low km 2 (%) NPCA (2,409) 542 (22%) 270 (50%) 129 (24%) 144 (27%) Niagara Region (1,871) 420 (22%) 20 (55%) 102 (24%) 89 (21%) City of Hamilton (27) 82 (5%) 18 (22%) 21 (26%) 4 (5%) Haldimand County (02) 40 (1%) 22 (55%) 6 (15%) 12 (0%) Note: some disagreement between sum areas and individual values is caused by rounding of significant digits Significant groundwater recharge areas are subdivided by the groundwater vulnerability and assigned scores of 6, 4 or 2 for groundwater vulnerabilities of high, medium and low, respectively. This is according to Assessment Report Technical Rules 80 and 81 (Table.2).. Uncertainty Table.2 SGRAs Vulnerability Score Groundwater Vulnerability Vulnerability Score High 6 Medium 4 Low 2 The Assessment Report Technical Rules 1, 14 and 15 (MOE, 2009) provide the following instructions for analysis of uncertainty. Rules pertaining to surface water intake protection zones, i.e. 1() and 1(4) were not included. NPCA 1

15 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area Part I.4 Uncertainty analysis Water quality 1. An analysis of the uncertainty, characterized by high or low shall be made in respect of the following: (1) the assessment of the vulnerability of groundwater throughout the area undertaken in accordance with Part IV; (2) the delineation of highly vulnerable aquifers, significant groundwater recharge areas and wellhead protection areas undertaken in accordance with Part V; (5) the assessment of the vulnerability of significant groundwater recharge areas, highly vulnerable aquifers and wellhead protection areas undertaken in accordance with Part VII; 14. The following factors shall be considered in an analysis conducted for the purpose of rule 1; (1) the distribution, variability, quality and relevance of data used in the preparation of the assessment report; (2) the ability of the methods and models used to accurately reflect the flow processes in the hydrological systeml () the quality assurance and quality control procedures applied; (4) the extent and level of calibration and validation achieved for models used or calculations or general assessments completed; (5) for the purpose of subrule 1(1), the accuracy to which groundwater vulnerability categories effectively assess the relative vulnerability of the underlying hydrogeological features; and 15. An uncertainty factor of high or low shall be assigned to each vulnerable area delineated based on the results of the analysis conducted under rule 1. The overall confidence in the Vulnerability Assessment as per Table. is 7 out of a possible 10. A value greater than 6 is assumed to reflect sufficient confidence that the results can be relied on for the purpose of the Vulnerability Analysis. The Uncertainty Score recommended for the NPSP Area Vulnerability Assessment based on Table. is Low. This uncertainty score reflects the combination of the confidence scoring assigned from the assessment of the quantity, quality and distribution of the available data. The uncertainty scoring suggests a high level of comfort in how representative the generated vulnerability scoring is for the NPSP area and how well it corresponds to the available data and previous work completed by others in the area. However there are two potential areas of lower confidence within the overall assessment. These are the (i) delineation of the vulnerability of the contact-zone aquifer and (ii) including transport pathway adjustments. The delineation of the GwISI contact-zone aquifer vulnerability is largely a function of the MOE water well records, not the actual stratigraphy. Consequently, some higher NPCA 14

16 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area vulnerability areas where wells are not completed, may not have been mapped. Also the contouring procedure is of the well data, not the aquifer, and may not have connected higher vulnerability zones because of limitations of this automated process. Both the exact location, and the status, of wells (water, oil and gas) considered to be transport pathways are unknown. However by their inclusion in the transport pathways assessment it is a conservative approach to address their potential to contaminate the aquifers. As part of the uncertainty analysis peer review of this report was completed by two firms, Jagger Hims Limited a division of GENIVAR and Terra-Dynamics Limited. The Jagger Hims Limited peer review is located in Appendix C. Terra-Dynamics Limited comments were largely editorial and were directly incorporated into the report. NPCA 15

17 Confidence Score (x/10) 7 Aquifer(s) Considered: Qualitative Assessment of Conceptual Understanding: Is the Groundwater Flow System Simple, Uniform? Does Groundwater Flow reflect topography & regional watershed drainage? Are there other reasonable interpretations of Groundwater Flow System? Are watershed/surface water interactions satisfactorily represented? Is the Aquifer Confined? Is the Target Aquifer in a complex Groundwater Flow System? Is the Target Aquifer in fractured rock? TABLE.: QUALIFICATION OF UNCERTAINTY Part 1. Assessment of Available Data Water Table/ Uppermost Aquifer Y Y N Y Y Y N Target Aquifer Yes at a regional scale assessment level Predominantly Other Aquifers Yes but regional scale assessment equivalent porous media approach acceptable Part 2. Assessment of Vulnerability Assessment 7.5 Vulnerability Method (Evaluate one method Only): Based on/considers Regional Stratigraphic Interpretations: Based on/considers Local (Individual Borehole) Interpretations: Does Vulnerability Assessment reasonably reflect data? Is Vulnerability Assessment Consistent with Regional Understanding? Basic Hydrogeological Evaluation Intrinsic Susceptibility Index (ISI) Aquifer Vulnerability Index (AVI) WAAT/ SAAT/ SWAT Detailed Hydrogeological Evaluation Progressive Evaluation (more than one approach) X X Y Y N Y Y LOW Assessment of Available Data/Interpretation Assessment of Vulnerability RECOMMENDED UNCERTAINTY SCORE Part. Uncertainty Assessment :08 AM M:\Source Wtr Protection\HVAs\Table _ - Qualification of Uncertainty.xls

18 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area 4. Next Steps This section describes potential future efforts to improve protection of highly vulnerable aquifers. It is recommended that improvement in the protection of groundwater supplies be a priority goal for the Source Protection Plan and Provincial Policy Statement implementation in the Niagara Peninsula Source Protection Area. 4.1 Potential Source Protection Plan Concepts Consideration should be given to multi-agency policy development, monitoring and approvals. This is to address the complex nature of groundwater protection, supply and legislation. The following are some identified agencies and the areas of their mandate pertaining to groundwater. Public Health communal and private water supplies; Public Works Part 8 Building Code sewage system approvals; Municipal Building Officials Geothermal approvals and some Part 8 Building Code sewage system approvals; Niagara Region District Office Ministry of the Environment Wells regulation, as well as permits to take water, certificates of approval, permits to discharge and waste disposal; and Conservation Authority hydrogeologic study reviews, mapping of significant and vulnerable groundwater areas. To protect, improve and restore groundwater supplies, it is also recommended the Source Water Protection Plan include requirements for groundwater protection. Some possible approaches include: A multi-agency well construction improvement program. This could include for the government and the public: o Targeted educational programs, e.g. flush-mounted monitoring wells and flowing wells are not allowed; o Construction bonds with government approvals, e.g. funds secured for well decommissioning prior to construction; and o Active well status commenting in reporting, e.g. party commitment to annual monitoring. Water use surveys (e.g. private well types and/or cisterns) in highly vulnerable aquifers; Tertiary sewage treatment system requirements, rather than conventional systems, on highly vulnerable aquifers. This could help reduce groundwater contaminants such as nitrate. Analytical wellhead protection area mapping for communal water supply systems; Requirements for licensed drilling contractors in construction of closed loop geothermal installations; and NPCA 17

19 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area Pit and quarry rehabilitation plans that meet, improve or protect pre-development groundwater vulnerability in up-gradient areas. Some programs to reduce groundwater vulnerability for consideration include: Locating and confirming unknown status well locations; Water supply well-upgrade incentive funding program; and NPCA aquifer system hydrogeologic mapping program. 4.2 Provincial Policy Statement Highly vulnerable aquifers are to be protected under the Provincial Policy Statement (PPS) ( Ministry of Municipal Affairs and Housing, 2005). Under the PPS, the NPCA, as a planning authority is required to: protect, improve or restore the quality and quantity of water by: d) implementing necessary restrictions on development and site alteration to: 1. protect all.designated vulnerable areas; and 2. protect, improve or restore vulnerable.groundwater ; NPCA PPS groundwater vulnerability mapping should be updated to correspond with this report Contaminant Management Recognizing the vulnerability of Highly Vulnerable Aquifers, requirements for contaminant management plans are also recommended. Contaminant management plans were recommended for Highly Vulnerable Aquifers in guidance prepared for the Conservation Authorities Moraine Coalition (CAMC) (Ogilvie, Ogilvie & Company and Anthony Usher Planning Consultant, 2005). The CAMC document recommended, under development approvals, contaminant management plans for Highly Vulnerable Aquifers and: High and moderate threat land uses and/or contaminant storage. Their examples of high threat land uses included but were not limited to waste management facilities, airports, lagoons for sewage treatment, and auto wrecking and salvage yards. This could include site-specific management such as double-walled fuel storage tanks with a monitoring program; and New or expanded agricultural uses greater than 5 nutrient units of manure per year, e.g. more than milking Holstein cows Emerging Challenges Future challenges to the protection of highly vulnerable aquifers include increased transport pathways that reduce natural protection and may increase groundwater vulnerability. Examples include: Priority aggregate extraction areas considered to be important in ensuring an adequate resource base for the future, i.e. for possible resource development, and representing areas in which a major resource is known to exist ( Geological NPCA 18

20 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area Survey, 1985). These include considerable areas of select bedrock resource in the municipalities of Grimsby, Lincoln, City of Hamilton, West Lincoln, Wainfleet, Port Colborne and Fort. As well as additional areas of primary significance for sand and gravel extraction in the municipality of Pelham. Earth Energy Systems, or more commonly known as geothermal systems, may have negative implications for groundwater protection. For example, closed loop installations do not require installation by a trained licensed drilling contractor. 4. Future Updates Data Gaps Future updates of Highly Vulnerable Aquifers should be based upon: A three-dimensional hydrostratigraphic model, which would include mapping of aquifer and aquitard extents and incorporate golden spike datasets; Subwatershed-scale water table mapping including both the fractured upper clay and uppermost drilled well aquifer systems; Improved understanding of the number and locations of water supply systems, e.g. regulated communal systems, cisterns, dug wells and drilled wells; and Field inventory of transport pathways, e.g. former water supply wells requiring abandonment. NPCA 19

21 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area 5. References Blackport & Associates, Waterloo Hydrogeologic, Inc., Hydrogeologic Assessment of the Fonthill Kame-Delta Complex. Technica l Appendix to the NPCA Groundwater Study. Charlesworth and Associates, and SNC-Lavalin Engineers and Constructors, Hamilton Groundwater Resources Characterization and Wellhead Protection Partnership Study. Report to the City of Hamilton. CH2MHill, MacViro and Philips Engineering, 200a. Niagara Water Quality Protection Strategy, Technical Report Phase 2. Prepared for Regional Municipality of Niag ara an d th e Niagara Peninsula Conservation Authority. CH2MHill, MacViro and Philips Engineering, 200b. Niagara Water Quality Protection Strategy, Final Technical Report (Volume 2,), Local Management Areas Summaries. Prepared for Regional Municipality of Niagara and the Niagara Peninsula Conservation Authority. EarthFX, Aquifer Vulnerability Mapping for Norfolk County, Catfish Creek and Kettle Creek Watersheds. Prepared for the Source Protection Region Grand River Conservation Authority. Fetter, C.W., Applied Hydrogeology. Third Edition, Prentice Hall, New Jersey. Freeze, R.A. and Cherry, J.A, Groundwater. Prentice Hall, New Jersey Frind, E.O., Molson, J.W. and Rudolph, D.L., Well Vulnerability: A Quantitative Approach for Source Water Protection. Ground Water, Vol.44, No.5, pages Frind, E.O., Theoretical analysis of aquifer response due to dewatering at W elland. Canadian Geotechnical Journal, Vol. 7, No. 205, Pages Gartner Lee Limited, 1987a. Water Resources of the Niagara Frontier and the Welland River Drainage Basin. Prepared for the Ministry of the Environment. Gartner Lee Limited, 1987b. NPCA 20

22 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area Site Assessment Phase 4B: Geology, Hydrogeology and Geotechnics, Baseline Conditions. Prepared for the W aste Management Corporation, Volum es 1, 2 and. Gartner Lee Limited, Site Selection Process Phase 4A: Selection of a Preferred Site(s) Geologic, Hydrogeologic, and Geotechnical Considerations. Prepared for W aste Management Corporation. Hamilton Conservation Authority, DRAFT Groundwater Resources Study. Prepared for Ministry of Northern Development and Mines, Geological Survey. Jagger Hims Limited, Technical Memorandum E1: Groundwater Vulnerability Assessment Blackstock. Prepared for the Regional Municipality of Durham. Johnston, Fraser, Personal communication. St.Lawrence Seaway Management Corporation. Kristjanson, Jamie, Personal communication. Niagara Region. Ministry of the Environment, Technical Rules: Assessment Report. Ministry of the Environment, 2006a. Assessment Report: Draft Guidance Module Groundwater Vulnerability Analysis. Ministry of the Environment, 2006b. Assessment Report: Draft Guidance Module 5 Issues Evaluation and Threats Inventory. Ministry of the Environment, Groundwater Studies 2001/2002 Technical Terms of Reference. Ministry of the Environment, Reference Document Model Microbial Contamination Control Plan for Municipal Supply Wells Under Direct Influence of Surface Water With Effective In Situ Filtration. Ministry of the Environment, Hydrogeological Environments and the Susceptibility of Ground Water to Contamination. Water Resources Branch, Map S100, Scale 1,000,000. NPCA 21

23 Groundwater Vulnerability Analysis Niagara Peninsula Source Protection Area Niagara Peninsula Conservation Authority, Watershed Characterization Report. Niagara Peninsula Conservation Authority and AquaResource Inc., Significant Groundwater Recharge Areas. Ogilvie, Ogilvie & Company and Anthony Usher Planning Consultant, Watershed Planning from Recommendations to Municipal Policies: A Guidance Document. Prepared for the York, Peel, Durham, Toronto Groundwater Study Conservation Authorities Moraine Coalition. Ministry of Municipal Affairs and Housing, Provincial Policy Statement Section of the Planning Act. Geological Survey, 200. Surficial Geology of Southern. Miscellaneous Release Data 128. Project Summary and Technical Document, 5 pp. Geological Survey, Quaternary Geology, seamless coverage of the province of : Geological Survey, Data Set 14. Geological Survey, Aggregate Resources Inventory of the City of Port Colborne and Town of Fort, Regional Municipality of Niagara, Southern. G eological Survey, Aggregate Resources Inventory Paper 117, 4 p., 7 tables, m aps, scale 1: S.S. Papadopulos & Associates, Inc., Peer Review of Aquifer Vulnerability Mapping for Norfolk County, County of Brant, Catfish Creek and Kettle Creek Watersheds (E arthfx Inco rporated, December 7, 2008). Prepared for the Grand River Conservation Authority. Warbick, John, Personal communication, Ministry of Agriculture and Food. Waterloo Hydrogeologic Inc., NPCA Groundwater Study. Prep ared for the Niagar a Peninsula Conservation Authority. NPCA 22

24 NPCA FIGURES

25 55 S r ou l Ha amilto n-h n o t ce Niagara-on-the- P r otection Reg i o n Grimsby St.Catharines New York State U.S.A. 405 Lincoln 6 20 Hamilton QEW La ke 406 ie Er 20 So Thorold ote e Pr urc West Lincoln Niagara Falls Pelham ctio nr eg Welland io n Haldimand Wainfleet Port Colborne Fort Disclaimer: This map is intended for illustrative purposes only. Figure is to be read in conjunction with the Niagara Peninsula Source Protection Area Groundwater Vulnerability Analysis Report. Please refer to report text for digital mapping sources. All Frames: North American Datum 198, Universal Transverse Mercator 6o Projection, Zone 17N, Central Meridian 81o West. Produced by the Niagara Peninsula Conservation Authority with data supplied under licence by members of the Geospatial Data Exchange, International Boundary Major Highways Highways Watercourse Ponds, Reservoirs, s Extended Context Area Source Water Protection Area Lower Tier Municipality Upper Tier Municipality Municipally Water Serviced Areas Kilometers Huron Legend 1:250,000 0 Groundwater Vulnerability Analysis Figure 1.1: Study Area Index Map Friday, November 1, 2009

26 55 S ce r ou l Ha amilto n-h n o t P r otection Reg i o n New York State U.S.A Iroquois Sand Plain 20 La ke QEW 406 ie Er 20 So ote e Pr urc ctio nr Fonthill Kame Delta Complex eg io n Dunnville Sand Plain Disclaimer: This map is intended for illustrative purposes only. Figure is to be read in conjunction with the Niagara Peninsula Source Protection Area Groundwater Vulnerability Analysis Report. Please refer to report text for digital mapping sources. All Frames: North American Datum 198, Universal Transverse Mercator 6o Projection, Zone 17N, Central Meridian 81o West. Produced by the Niagara Peninsula Conservation Authority with data supplied under licence by members of the Geospatial Data Exchange, International Boundary Major Highways Highways Watercourse Ponds, Reservoirs, s Extended Context Area Source Water Protection Area Lower Tier Municipality Upper Tier Municipality Water Supply Wells Other Water Wells Water Supply Wells Surficial Overburden Aquifers Kilometers Huron Legend 1:250,000 0 Groundwater Vulnerability Analysis Figure 1.2: NPSP Area Prominent Surficial Overburden Aquifers Index Map Friday, November 1, 2009

27 55 S ce r ou l Ha amilto n-h n o t P r otection Reg i o n New York State U.S.A QEW La ke 406 ie Er 20 So ote e Pr urc ctio nr eg io n Disclaimer: This map is intended for illustrative purposes only. Figure is to be read in conjunction with the Niagara Peninsula Source Protection Area Groundwater Vulnerability Analysis Report. Please refer to report text for digital mapping sources. All Frames: North American Datum 198, Universal Transverse Mercator 6o Projection, Zone 17N, Central Meridian 81o West. Produced by the Niagara Peninsula Conservation Authority with data supplied under licence by members of the Geospatial Data Exchange, Legend International Boundary Major Highways Highways Watercourse Ponds, Reservoirs, s Extended Context Area Source Water Protection Area Contour 5 m Lower Tier Municipality Upper Tier Municipality Other Water Wells Water Supply Wells Bedrock Sand and Gravel Aquifer Thickness Water Supply Aquifers Above Bedrock (m) Bois Blanc Formation Onondaga Formation Guelph Formation Lockport Formation 1:250, Kilometers Huron Groundwater Vulnerability Analysis Figure 1.: NPSP Area Contact-Zone and Prominent Bedrock Aquifers Index Map Friday, November 1, 2009

28 55 S ce r ou l Ha amilto n-h n o t P r otection Reg i o n New York State U.S.A QEW La ke 406 ie Er 20 So ote e Pr urc ctio nr eg io n Disclaimer: This map is intended for illustrative purposes only. Figure is to be read in conjunction with the Niagara Peninsula Source Protection Area Groundwater Vulnerability Analysis Report. Please refer to report text for digital mapping sources. All Frames: North American Datum 198, Universal Transverse Mercator 6o Projection, Zone 17N, Central Meridian 81o West. Produced by the Niagara Peninsula Conservation Authority with data supplied under licence by members of the Geospatial Data Exchange, Legend International Boundary Major Highways Highways Watercourse Ponds, Reservoirs, s Extended Context Area Source Water Protection Area Lower Tier Municipality Upper Tier Municipality Groundwater Susceptibility (GwISI) High Medium Low GwISI Data Points High Medium Low 1:250, Kilometers Huron Groundwater Vulnerability Analysis Figure 2.1: Rule 7(1)/8(1) Groundwater Vulnerability Intrinsic Susceptibility Index Index Map Friday, November 1, 2009

29 55 S ce r ou l Ha amilto n-h n o t P r otection Reg i o n Niagara-on-the- Grimsby St.Catharines New York State U.S.A. 405 Lincoln 6 20 Hamilton La ke QEW 406 ie Er 20 So Thorold ote e Pr urc West Lincoln Niagara Falls Pelham ctio nr eg Welland io n Haldimand Wainfleet Port Colborne Fort Disclaimer: This map is intended for illustrative purposes only. Figure is to be read in conjunction with the Niagara Peninsula Source Protection Area Groundwater Vulnerability Analysis. Please refer to report text for digital mapping sources. All Frames: North American Datum 198, Universal Transverse Mercator 6o Projection, Zone 17N, Central Meridian 81o West. Produced by the Niagara Peninsula Conservation Authority with data supplied under licence by members of the Geospatial Data Exchange, Legend International Boundary Major Highways Highways Roads Extended Context Area Niagara Peninsula Source Water Protection Area Lower Tier Municipality Upper Tier Municipality Bedrock Outcrop Contour 5 m Interval 5 m Thickness Overburden thickness (m) High : 107 * Bedrock outcrop denotes areas where there is less than 1m of overburden Low : 0 1:250, Kilometers Huron Groundwater Vulnerability Analysis Figure 2.2: Overburden Thickness Index Map Friday, November 1, 2009

30 55 S ce r ou l Ha amilto n-h n o t P r otection Reg i o n New York State U.S.A. Niagara Escarpment Iroquois Sand Plain 20 La ke QEW 406 ie Er 20 So ote e Pr urc ctio nr Fonthill Kame Delta Complex eg io n Onondaga Escarpment Dunnville Sand Plain Disclaimer: This map is intended for illustrative purposes only. Figure is to be read in conjunction with the Niagara Peninsula Source Protection Area Groundwater Vulnerability Analysis Report. Please refer to report text for digital mapping sources. All Frames: North American Datum 198, Universal Transverse Mercator 6o Projection, Zone 17N, Central Meridian 81o West. Produced by the Niagara Peninsula Conservation Authority with data supplied under licence by members of the Geospatial Data Exchange, Legend International Boundary Major Highways Highways Watercourse Ponds, Reservoirs, s Extended Context Area Source Water Protection Area Groundwater Vulnerabilty (AVI) High (Sand and / or Gravel at Surface) Lower Tier Municipality High (Bedrock Outcrop) Upper Tier Municipality High (Karst Area) High ( < 5 m overburden) >5 1:250, Kilometers Huron Groundwater Vulnerability Analysis Figure 2.: Rule 7(2)-8(1) Groundwater Vulnerability Aquifer Vulnerability Index Index Map Friday, November 1, 2009

31 55 S ce r ou l Ha amilto n-h n o t P r otection Reg i o n New York State U.S.A QEW La ke 406 ie Er 20 So ote e Pr urc ctio nr eg io n Disclaimer: This map is intended for illustrative purposes only. Figure is to be read in conjunction with the Niagara Peninsula Source Protection Area Groundwater Vulnerability Analysis Report. Please refer to report text for digital mapping sources. All Frames: North American Datum 198, Universal Transverse Mercator 6o Projection, Zone 17N, Central Meridian 81o West. Produced by the Niagara Peninsula Conservation Authority with data supplied under licence by members of the Geospatial Data Exchange, Legend International Boundary Major Highways Highways Watercourse Ponds, Reservoirs, s Extended Context Area Source Water Protection Area Lower Tier Municipality Upper Tier Municipality Groundwater Vulnerability High Medium Low 1:250, Kilometers Huron Groundwater Vulnerability Analysis Figure 2.4: Groundwater Vulnerability Rules 7(1)/7(2)/8(1) Index Map Friday, November 1, 2009

32 Disclaimer: This map is intended for illustrative purposes only. Figure is to be read in conjunction with the Niagara Peninsula Source Protection Area Groundwater Vulnerability Analysis Report. Please refer to report text for digital mapping sources. All Frames: North American Datum 198, Universal Transverse Mercator 6 o Projection, Zone 17N, Central Meridian 81 o West. Produced by the Niagara Peninsula Conservation Authority with data supplied under licence by members of the Geospatial Data Exchange, Halton-Hamilton Source P rotection Regi on Grimsby 6 Lincoln Hamilton 20 Source Protection Region West Lincoln Haldimand 1:100, Kilometers Legend International Boundary Major Highways Highways Watercourse Ponds, Reservoirs, s Extended Context Area Source Water Protection Area Welland Canal on Bedrock Lower Tier Municipality Upper Tier Municipality Municipally Serviced Water Areas Aggregate Operations Cluster Wells (>= 6 Wells in 100 m Radius) Unknown Status Oil and Gas Wells Municipally Serviced Areas WWIS Wells MOE WWIS pre-2000 Groundwater Vulnerability (High) Huron Index Map Groundwater Vulnerability Analysis Figure 2.5a: Transport Pathways Friday, November 1, 2009

33 Disclaimer: This map is intended for illustrative purposes only. Figure is to be read in conjunction with the Niagara Peninsula Source Protection Area Groundwater Vulnerability Analysis Report. Please refer to report text for digital mapping sources. All Frames: North American Datum 198, Universal Transverse Mercator 6o Projection, Zone 17N, Central Meridian 81o West. Produced by the Niagara Peninsula Conservation Authority with data supplied under licence by members of the Geospatial Data Exchange, Niagara-on-the- St.Catharines Grimsby 405 Lincoln New York State U.S.A. QEW 406 Niagara Falls Thorold 20 Pelham West Lincoln 1:100, Kilometers Legend International Boundary Major Highways Highways Watercourse Ponds, Reservoirs, s Extended Context Area Source Water Protection Area Welland Canal on Bedrock Lower Tier Municipality Upper Tier Municipality Municipally Serviced Water Areas Aggregate Operations Cluster Wells (>= 6 Wells in 100 m Radius) Unknown Status Oil and Gas Wells Municipally Serviced Areas WWIS Wells MOE WWIS pre-2000 Groundwater Vulnerability (High) Huron Groundwater Vulnerability Analysis Figure 2.5b: Transport Pathways Index Map Friday, November 1, 2009

34 Thorold New York State U.S.A. Pelham Niagara Falls West Lincoln Welland Fort Wainfleet Port Colborne Disclaimer: This map is intended for illustrative purposes only. Figure is to be read in conjunction with the Niagara Peninsula Source Protection Area Groundwater Vulnerability Analysis Report. Please refer to report text for digital mapping sources. All Frames: North American Datum 198, Universal Transverse Mercator 6o Projection, Zone 17N, Central Meridian 81o West. Produced by the Niagara Peninsula Conservation Authority with data supplied under licence by members of the Geospatial Data Exchange, Legend International Boundary Major Highways Highways Watercourse Ponds, Reservoirs, s Extended Context Area Source Water Protection Area Welland Canal on Bedrock Lower Tier Municipality Upper Tier Municipality Municipally Serviced Water Areas Aggregate Operations Cluster Wells (>= 6 Wells in 100 m Radius) Unknown Status Oil and Gas Wells Municipally Serviced Areas WWIS Wells MOE WWIS pre-2000 Groundwater Vulnerability (High) 1:100, Kilometers Huron Groundwater Vulnerability Analysis Figure 2.5c: Transport Pathways Index Map Friday, November 1, 2009

35 Hamilton West Lincoln Pelham New York State U.S.A. Haldimand Wainfleet Source Protection Region Disclaimer: This map is intended for illustrative purposes only. Figure is to be read in conjunction with the Niagara Peninsula Source Protection Area Groundwater Vulnerability Analysis Report. Please refer to report text for digital mapping sources. All Frames: North American Datum 198, Universal Transverse Mercator 6 o Projection, Zone 17N, Central Meridian 81 o West. Produced by the Niagara Peninsula Conservation Authority with data supplied under licence by members of the Geospatial Data Exchange, :100, Kilometers Legend International Boundary Major Highways Highways Watercourse Ponds, Reservoirs, s Extended Context Area Source Water Protection Area Welland Canal on Bedrock Lower Tier Municipality Upper Tier Municipality Municipally Serviced Water Areas Aggregate Operations Cluster Wells (>= 6 Wells in 100 m Radius) Unknown Status Oil and Gas Wells Municipally Serviced Areas WWIS Wells MOE WWIS pre-2000 Groundwater Vulnerability (High) Huron Index Map Groundwater Vulnerability Analysis Figure 2.5d: Transport Pathways Friday, November 1, 2009

36 55 S ce r ou l Ha amilto n-h n o t P r otection Reg i o n New York State U.S.A QEW La ke 406 ie Er 20 So ote e Pr urc ctio nr eg io n Disclaimer: This map is intended for illustrative purposes only. Figure is to be read in conjunction with the Niagara Peninsula Source Protection Area Groundwater Vulnerability Analysis Report. Please refer to report text for digital mapping sources. All Frames: North American Datum 198, Universal Transverse Mercator 6o Projection, Zone 17N, Central Meridian 81o West. Produced by the Niagara Peninsula Conservation Authority with data supplied under licence by members of the Geospatial Data Exchange, Legend International Boundary Major Highways Highways Watercourse Ponds, Reservoirs, s Extended Context Area Source Water Protection Area Lower Tier Municipality Upper Tier Municipality Groundwater Vulnerability High Medium Low 1:250, Kilometers Huron Groundwater Vulnerability Analysis Figure 2.6: Groundwater Vulnerability Rules 7,8,9 and 40 Index Map Friday, November 1, 2009

37 55 S ce r ou l Ha amilto n-h n o t P r otection Reg i o n New York State U.S.A QEW La ke 406 ie Er 20 So ote e Pr urc ctio nr eg io n Disclaimer: This map is intended for illustrative purposes only. Figure is to be read in conjunction with the Niagara Peninsula Source Protection Area Groundwater Vulnerability Analysis Report. Please refer to report text for digital mapping sources. All Frames: North American Datum 198, Universal Transverse Mercator 6o Projection, Zone 17N, Central Meridian 81o West. Produced by the Niagara Peninsula Conservation Authority with data supplied under licence by members of the Geospatial Data Exchange, Legend International Boundary Major Highways Highways Watercourse Ponds, Reservoirs, s Extended Context Area Source Water Protection Area Lower Tier Municipality Upper Tier Municipality Groundwater Vulnerability High - Vulnerability Score 6 1:250, Kilometers Huron Groundwater Vulnerability Analysis Figure.1: Highly Vulnerable Aquifers Index Map Friday, November 1, 2009

38 55 S ce r ou l Ha amilto n-h n o t P r otection Reg i o n New York State U.S.A QEW La ke 406 ie Er 20 So ote e Pr urc ctio nr eg io n Disclaimer: This map is intended for illustrative purposes only. Figure is to be read in conjunction with the Niagara Peninsula Source Protection Area Groundwater Vulnerability Analysis Report. Please refer to report text for digital mapping sources. All Frames: North American Datum 198, Universal Transverse Mercator 6o Projection, Zone 17N, Central Meridian 81o West. Produced by the Niagara Peninsula Conservation Authority with data supplied under licence by members of the Geospatial Data Exchange, Legend International Boundary Major Highways Highways Watercourse Ponds, Reservoirs, s Extended Context Area Source Water Protection Area Lower Tier Municipality Upper Tier Municipality Groundwater Vulnerability and Score High - 6 Medium - 4 Low - 2 1:250, Kilometers Huron Groundwater Vulnerability Analysis Figure.2: Significant Groundwater Recharge Area Vulnerability Index Map Friday, November 1, 2009

39 NPCA Appendix A

40 15m Below Ground Level

41 Interpreted Groundwater Flow Directions 15m Below Ground Level

42 Interpreted Groundwater Flow Directions 15m Below Ground Level

43 NPCA Appendix B

44 MEMO DATE: November 0, 2009 FROM: Jaym RE: e Campbell Existing Vulnerability Mapping Review 1.0 OB JECTIVE: To com plete a review of existing regional-scale Nia gara Peni nsula So urce P rotection (NPSP) Area groundwater vulnerability maps for their suitability in the Source Water Protection Groundwater Vulnerability assessment. 2.0 OVERVIEW : Groundwater protection became a high-priority issue in since the Walkerton tragedy in However, provincial mapping of groundwater susceptibility to contamination began at least two decades before (Ministry of the Environment, 1980). In the three decades since, regional scale mapping of groundwater vulnerability has been completed a number of times in the Niagara Peninsula Source Protection (NPSP) Area. This has been done using both qualitative and quantitative methods (Gartner Lee Limited 1987, CH2MHill MacViro and Philips Engineering 200, Geological Survey 200 and Waterloo Hydrogeologic Inc. 2005) and across NPSP Area boundaries (Charlesworth and Associates and SNC-Lavalin 2006, Hamilton Conservation Authority 2006 and EarthFX 2008). The Niagara Peninsula Conservation Authority (NPCA) reviewed the above mentioned studies as pa rt of p reparing the NPSP Area Source Water Protection (SWP) Assessment Report. The M inistry of t he Environment (MOE) Assessment Report Techni cal Rules (M OE, 2008) re quire s uch an a nalysis th at inclu des i dentification of high, m edium an d lo w aquifer vulnerability as specific types of vulnerable areas that will be protected under the Clean Water Act (2006). Three types of groundwater vulnerability studies were reviewed: 1. Basic Hydrogeological Assessments (BHA) 2. Intrinsic Susceptibility Index (GwISI). Aquifer Vulnerability Index (AVI) 4. Surface to Aquifer Advection Time (SAAT) 2.1 Basic Hydrogeological Assessments: A Basic Hydrogeological Assessment (BHA) can be defined as: a qualitative approach where consideration is given to the available hydrogeological information and the relative vulnerability of the aquifer(s) assessed not directly involv(ing) numerical calculations or modelling. ( MOE, 2006a) This method is not explicitly mentioned in the Technical Rules (MOE, 2008) but may be considered acceptable by the Director in some cases under Rule Three sets of these BHA maps are available in the NPSP Area and they are discussed below Ministy of the Environment Gartner Lee Limited (1987) In the late 1980s, the Ministry of the Environment (MOE) inventoried surface and groundwater resources in the Niagara River and Welland River drainage basins (Gartner Lee Limited, 1987a). A series of maps were prepared entitled Ground Water Susceptibility to Contamination based upon a qualitative consideration of (i) the permeability of near-surface materials, (ii) groundwater movement and (iii) the presence of an aquitard and a major shallow bedrock aquifer less than 10 metres below ground surface (m bgs). Groundwater susceptibility categories included high, low and variable (Figure B.1). The initial mapping effort completed with respect to the boundaries of the Welland and Niagara River basins included 24% of these basins as highly susceptible.

45 Page 2 Existing Vulnerability Mapping Review November 0, 2009 The 10 mbgs criterion may seem overly conservative but was reasonable based on the consultant s experience in the Haldimand Clay Plain. Gartner Lee Limited had been working on a site selection process in Southern for facilities for the treatment and disposal of liquid industrial and hazardous wastes (Gartner Lee Limited, 1985). As part of the candidate site selection process, they had completed a number of very detailed hydrogeologic investigations on the thickness and competence of clay-based aquitards Niagara (Figure B.2) (Gartner Lee Limited, 1987b). Gartner Lee Limited determined that the at-surface, fractured portion of the clay plain, which they called the upper glaciolacustrine fractured zone, may extend to depths which range up to several metres. They described the upper 1 to m as intensely weathered and the most severely fractured. Fracture frequency in this fractured zone decreased rapidly with depth and fractures were present but infrequent below 5 m, while occasional, individual fractures were noted at greater depths ranging from 6 to 12 m (Gartner Lee Limited, 1985). These results agree with information determined as part of Niagara Region landfill investigations (Jamie Kristjanson Niagara Region, personal communication 2009). Freeze and Cherry (1979) had also previously noted that deposits of clayey or silty till and glaciolacustrine deposits in southern contain networks of hairline fractures which are essentially vertical and which are responsible for hydraulic conductivities one to three orders of magnitude greater than in unfractured materials. Gartner Lee Limited assigned this upper glaciolacustrine fractured zone a hydraulic conductivity of 10-8 m/s, two orders of magnitude greater than in the underlying unfractured materials. This higher hydraulic conductivity was conservatively applied over an interval of 5 m. The estimate of vertical groundwater velocities in the fractured zone was about four orders of magnitude greater than in the underlying unfractured materials. Vertical flow velocities of between 10-6 and 8x10-7 m/s were calculated. Based on less than 5 m of overburden, the time of travel to the underlying aquifer could be less than a year. Figure B.2 Locations of Candidate Sites While movement in the surficial shallow fracture clay flow system is essentially lateral, dug and bored wells were reported to obtain water supplies from this portion of the clay plain. Saturated fracture systems and silt or granular laminations within the lacustrine deposits are considered to be the source of water to such wells. In view of the fine-textured character of the deposits and the limited porosity of the fractures, yields to most shallow dug and bored wells are expected to be low and users likely rely on well-bore storage for periods of peak use. (Gartner Lee Limited, 1985)